Built-up sectional forging and method of making same



G. H. HIGGINS 1,723,036

BUILT-UP SECTIONAL FORGING AND METHOD OF MAKING SAME Aug. 6, 19:29.

Filed May 31, 1927 2 Sheets-Sheet GEORGE H. HIGGINS INVENT R.

ATTORNEY.

Aug. 6, 1929. G. H. HIGGINS BUILT-UP SECTIONAL FORGING AND METHOD OF IAKINGr SAIE F'il'edv May 31, 1927 2 Sheets-Sheet 2 ill Fla! .rl

IIIPIIIIFIII GEORGE H. mews INVENTOR.

ATTORNEY.

I hollow-forms of intricate Patented Aug. 6, 1929.

UNITED STATES PATENT OFFICE. A Y

GEORGE H. HIGGINS, 0F CORTLAND, NEW YORK, ASSIGNOR TO THE BREWER- TITOHENEB CORPORATION, OF CORTLAND, NEW YORK, A CORPORATION 0! NEW YORK.

BUILT-UP SECTIONAL FOBGING AND METHOD OF MAKING SAIE.

Application filed Kay 31,

This invention relates to the art of hollow metal forgings and more particularly to bell-shaped caps adapted to mount insulator discs as conventionally used in suspending high tension conductors for electric transmission lines or the like. The, primary object of my improvements is to effectively and economically make a chambered product of this character by a welded sectional forging process as distinguished from a solid forged or a casting process. Insulator caps are now generally formed as a united whole in the shape of an openmouthed bell equipt with attachment means at the top for supporting purposes while the interior of such hollow cap may provided with a reenforced cup ed-in rim or other suitable mouth contraction ada ted to secure a cement medium and positive hold the neck of an insulator disc within t e cap recess.

The present method of making such caps or the like contemplates using two or more similar drop forged fragmental wall sections such that when their corresponding edges are placed in alignment and t e abutting joint welded together, they will form a complete weathe roof ca unit of which the open mouth region may strengthened bya bead-likeenlargement of the undercut type. A further outstanding object is to both simplify and cheapen the cost of manufacture of worked metal insulator caps and otherwise to improve the reliability of such products. The use of my sectional forgings greatly facilitates the makin of recessed ro le which are usually found diflicult to abricate by conrather massive support ears for the insulator 1927. Serial No. 195,378.

cap in order to sustain the heavy line load coming thereon. Under changing tempera ture and other weather conditions, said cemented inset insulator neck member tends to grow in size and its expansion within the confining cap chamber is in turn likely to set up a variable radial stressof considerable magnitude in the surrounding metal walls; such cast cap walls must therefore be kept com aratively thick and heavy if they are safe y to carry their suspended line load and at the same time prevent rupture when subjected to the indicated radial stress.

A protective cap of this kind is usually interposed between each of a series of spaced multiple insulator units mounted in tandem and the number of units so disposed being dependent upon the high tension line voltage that is to be transmitted; it will be obvious thatthe metal spacing caps in question must possess the utmost of reliability in regard to structural material for the reason that it becomes extremely diflicult as well as expensive to replace any defective cap after it has been placed in service. I

The use of worked metal insulator ca s preferably of steel, allows of making t e wall thickness relatively thin because of the finer and closer grain resulting from rolling or swaging the metal; it also affords more uniform and stronger molecular structure for the same character of material than is attainable by casting methods. The allowable thinner wall of a circumscribing forged cap not only reduces material requirements but provides for more ample stretch to give greater assurance against cap failure when subjected to the most severe service conditions; the forging processes at the same time better lends itself to productive methods. Said saving in cap weight reduces the suspended line load'while the provision for less massive supporting ear sections makes for a more compact insulator assembly;

It is further emphasized that my invention aims to secure all' the advantages u use-.- by the resent solid forged type of insulator cap ut without being. obliged to hollow forge and perform the cited extra operation of cupping-in its mouth rim, or of machining attachment ears or sockets out of a single piece of stock. In my im roved built-up or smeaa the the g s P other new and useful results, the invention lower level than now prevails. As a further advant-a internally disposed reinforcing ribs may be forged within my bell-shaped chambers similar to those commonlyused in connection with .cast caps; PIOVISIOII has also been made to properly gather the stock in the dome region of my bell-shaped for ings with a view of imparting amp strength and rigidity to the structure as a whole.

To this end and the accomplishment of further consists in novel features of structure and manipulation, all 'of which will hereinafter be more fully described' Reference is had to the accompanying two sheets of drawings which are illustrative of a specific embodiment of my invention partlcularly as applied to forged insulator caps, in which like characters of reference indicate like parts, and in which:

' Fig. 1 represents an assembly of a series of alternatev insulator discs arranged in tandem, each interconnected by means of my cap devices and as a whole intended to suspend a high tension line wire.

Fig. 2 shows an enlarged transverse section as taken through one'of the tandem insulator units indicated in Fig; 1.

Fig. 3 illustrates in plan one shape of blank from which a half or'other fragmental section of my cap may be-formed up while Fig. 4 is a sectional view taken along line IVIV of Fig. 3.

Fig. 11A represents a fragmental to view of Fig. 4 to bring out a detail thereo Fig. 5 is a frontview of one style of .my half cap sections as formed from said blank, while Figs. 6 and 7 respectively are bottom and side views thereof.

Fig. 8 shows an assembly of two such sectional caps ready to be butt welded along their parting faces; Figs. 9 and 10 are the respective bottom and top view of the same,

Fig. 11 indicates a modified type of welded sectional cap in that a ball and socket type of pin sus ension isv here used to replace the space ear type of lugs previously shown; and Fig.'l2 is an elevational view g f section taken along line XII-XII of ig.11.

Referring first to Fig. 1, this shows a series of multi le insulator discs such as A, A", etc. of w ich the uppermost may be suspended in any suitable manner upon a pole cross arm 0 or the like; these discs may be respectively interconnected in tandem by means of chambered metal caps B, B, etc. which cooperate with link pins to form a built-up composite insulator in the conventional fashion and of which the lowermost joined parting line B Each of said fragmental cap sections may further be equipt with apertured complementing ear lugs such as. B or B, through which the cottered rivet pin C, may be mounted. The lowermost contracted mouth edge of said adjoined bell-shaped sections may respectively be provided with the cupped-in rim member B,

and B and when adjoined together, they form a continuous undercut mouth opening into which may be mounted the shank or neck A," of the glass, orcelain or similar style of insulator disc Said disc may further be provided with a centrally disposed socket A," into which the headed disc pin 0 may be firmly cemented or otherwise secured and which link-like member is provided with a bearing hole C adapted to engage a rivet pin such as C The insulator shank A, may also be fastened into the radially recessed cap cavity, preferably by I means of cement or other suitable filler medium indicated as A The previously described associated details are merely intended to point out the disposition and general purpose of my improved insulator cap but such details other than a particular formation and welding of the segmental cap are substantially of the conventional type.

Taking up now the making of my sectional cap structure, the first step may reside in rough forging a relatively thin corrugated blank or blocking impression I) as made of suitable steel stock or the like. This substantially flat but ridged blank may be given any desired shape but for illustrative purposes, is shown in Figs. 3 and 4 as drop forged into a fan shaped impression having a thickened wing lug D but otherwise being mainly kept trapezoidal in plan outline. The opposite irregular rounded edges D and D of this blank are intended to conform generall to the developed shape of a bell-like or ot er hollow forging which it is desired to produce. The two transversely disposed side edges D and D thereof are preferably sloped or ta ered toward each other to provide for a aring semi-circular or other arcuate shape that is adapted to form up the skirt portion of my sectional cap members in the manner presently to be set forth.

The major portion of the flat face D,

which later forms the outside surface of my semi-cap shell, ma -be ke t substantially smooth except for .t e initia 1y raised ridges 4, and D which preferably run crosswise between said side edges D, and D, and the inner blank surface D, may be similarly provided with complementary ridges D, and D The ridge or ridges D, and D, constitiite distributed or gathered metal stock for the purpose of subsequently forming up a reinforcement for the cupped-in mouth portion of my inturned bell-shaped section; said ridge or ridges D and D represent athered metal stock that is utilized in drawing down the dome wall ortion B and thereby insuring ample thickness at this point in the finished forging as well as in the filleted projecting lip portion designated her and also to better as B in Fig. 7. The wing lug D provides the necessary metal required for forging the bell ear B Intermediate the ridges D, and D there may also be provided a plurality of further similar ridges or corrugations such as D shown in dotted and dashed lines. These raised blank elements subsequently serve to form one or more perimetrically disposed rib means preferably directed toward the interior of the formed up cap skirt. The ridges D serve to reinforce the skirt cham- 'p the insulator neck therein but since t e use of such rib corrugations is not essential, they can readily be dispensed with.

Said blank D is referably drop forged down from relative y heavy stock and the primary purpose in so roughing out the described lank is to obviate subjecting the -more delicate finishing dies to undue wear and tear. It is pointed out that the finished sectional forging might be formed u without first forming the described b ocking impression although such. procedure is likely to lead to excessive cold-shuts and otherwise prove inexpedient from a manufacturing standpoint.

As a second step in the makin of my insulator cap, said blankD may be 'rop' forged or otherwise swaged up into the cup shape indicated by Figs. 5 to 7 inclusive, and in this instance a partial wall section is shown as provided with internal ribs D,. When made in semicircular or other arcuate shape, the skirt portion B may be brought up so that its respective terminal edges B, and B fall into substantial alignment and these outer parting edges are at the same time preferably scarfed back more or less as indicated by B, to facilitate welding together the complementary cap fragments. The edge ridge D, of said blank may be simultaneously shaped up to form an inturned rim portion B as shown in Fig. 5 in order that the tubular skirt B of my bell-shaped forging may mume a cupped-in v mouthvdesired to avoid inte erence on portion that-is contracted in size with respect to the adjacent interior portion of the recessed chamber. Said thickened undercut lips B, and B, after being welded together serve as an endless band ada ted to reinforce the open mouth of the be -shaped cap and augment the downward holding power on part of the inserted insulator disc. It is emphasized that the present forging method afiords an advantage overconventional practice, in that the mouth edge of my cap rim does notneed to be separately crimped inwardly 'after'leaving the forgin dies; as a consequence, this modification al ows of giving the rim a relatively stifi' bead-like profile materially heavier than the thickness of its adjacent skirt wall portion.

In the completed forging, the com lementary blank rid es D and D will t en have been drawn own to furnish metal for filli up the dome wall portion 13,, the ear let B and the u standing lip B The upper. portion of sai half cup wall section is shown as fully closed by the transve'rsely disposed dome or head wall rtion B made to merge with the arcuate skirt wall as shown in Fig. 5, while in other cases it may be expedient to carry said scarfing along the inside edge of the butt seam or to resort to a. combination of inner and outer edge scarfing. The latter mode of inverse scarfingis especially ertinent should it be art of the attaching means when applying t e weldi n medium; the scarfing may then be appli along the inner edge of the' transverse dome rtion B while the outside edge of the skirt 1 remains as indicated in Fig. 12.

Simultaneous with the forming of the described sectional cap elements, attachment means such as the ear lugs B or the like may be shaped up out of the projecting wing portion D of said blank; in the present 1nstance this may readily be accomplished by parting a drop forging die along the offset line ZZ as indicated in Fig. 7. If desired, the lug aperture B may be either punched or struck up at the time of forgin the described fragmental cap section uch forgings can readily be held to fairly accurate dimensions and it now merely remains to trim the flash preferably including that of the aperture B,, which then complete the tial cap sections may readily be assembled and held into abutment in the fashion shown in Fig. 8 where the respective scarfed edges B may be adjoined toform a common V shaped notch extending around the exterior or interior of said seam line or a combination thereof as previously indicated. This notch may likewise be made to extend clear around both the interior'and exterior edge faces of the cap and thus provide for a double bevel weld joint should this be desired; it is to be understood however, that my sectional caps can also be welded together without having to scarf back any of the abuttin seam edges.

The thin? step in making of my insulator cap consists in welding together the abutting seam of such sectional cap fragments to form a unitary cap structure and this may be accomplished in any ap roved man-- ner as by arc, spot, oxy-acety ene, or any other suitable welding method. This cited drop forged V notch facilitatesthe welding operation but is not essential, and said butt 'oint ma be either flush welded orbuilt up into a Her head extending beyond the outer limits of said groove. The deposit of welding material is intended to be thoroughly sweat in between the adjoinin seamfaces of the scarfed butt weld in the ashion re resented by shaded lines B, of Fi 9 w ich makes up a joint virtually equ to full plate strength; It will be obvious that instead of formin a blunt bevel V notch as shown, the described forging process may likewise be used in striking u longer coopcrating scarfed edge adapted to be lap welded along the abutting seam of the semicap portions.

, orthe purpose of insuring augmented stren th in the seam weld B,, it has been found expedient to enlarge the cross-sectional area of the abutting welded cap edges particularly in the end regions of sand seam B lying adjacent to the cupped-in rim portions B and B". is may readily be accomplished by further provid' the described blank D with an u set ulge or wedge-shaped swell such as 11 or D respectively disposed on the opposite ends of one or both of the ridges D or D in the mannerindicated in Fig. 3. When a blank of this kind is shaped up into a sectional cap, the respective outermost swells are preferably arranged to extend tangentially out of the circumscribing surface of the skirt B in the fashion shown in Figs. 5 and 6, the aforesaid blank swells being there sha ed into raised seam lips B and B, an servin to reinforce the weld of the respective a utting rim end portions B, and B,.

While the last named figures show said lips B and B, as confined to the rim or outer free end portions of the welded seam B,, it will be apparent that such seam enlargement may likewise be extended to reach further along the entire skirt seam and 'to- Ward the dome of my bell-shaped forged sections should this be desired. Breakdown pull tests subjecting an assembled ca unit to abnormally heavy longitudinal ,loa

show however that the inturned rim edge of such insulator caps is the element that is most likely to first give awe. and that in such event, the resulting crac tends to rip progressively upward into the lighter skirt walls. B reinforcing the inturned rim through t e thickened blank ridge D and further reinforcing the ends of this ridge by means of the swells D as described the cap proper is not only made materially stronger against heavy downward line load but the welded joints of said endless rim is also correspondingly im roved by reason of the supplemental deposit of metal and the enlarged weld surface afforded at this critical point by the respective pairs of abutting seam lips B and B,'.

After removal from the gig, the welded cap seam may if necessary, be ground off to remove superfluous stock and otherwise trim up the finished product, whereupon it is usually galvanized and becomes ready for assembling therein of the neck A 7 of the insulator disc A which may readily be secured into the recessed cap bymeans of the filler medium A," already described. Said this type each equipped with an insulator and carrying an interconnectin disc pin such as C may now be installed in the tandem fashion indicated in Fig. 1 where my integrally formed cap ears such as B, are made to serve for supporting purposes; the assembling of insulator parts constitutes the final step in my method of making welded sectional forgings should they be applied to insulator caps.

Figs. 11 and 12 show a modified type of sectional welded cap in which the internal ribs D have been omitted while the complementar ear pieces are here replaced by a ball an socket support fastening of the open type as disposed within the dome of said cap. In this disclosure, the blank may still be drop forged inthe manner previously described; the dies would however be modified somewhat to produce a set of ii hthand and left-hand sectional cap mem rs designated as B and B each having a complementary recessed semi-spherical socket dome portion such as B which when welded together, form the common recess B In this instance, a ball head type of disc pin such as C, is preferably used and this is intended to be freely entered into the socket and locked therein by the split pin C in the conventional manner. It will be observed that the abutting cap edges may be oppositely scarfed along the entire length of the welded seam in the fashion previously described and as before, these complementary beveled edges are preferably struck up simultaneousl with the shaping up of the requisite blan D. By meansof the disclosed method of making forged insulator caps, it again becomes possible to form an undercut socket for receiving the head of the support pin without need of milling or otherwise machining the required ball recess. My improved method brings about a decided cut in cost of fabrication over prevailing forging methods and there is produced a finished unitary cap product of the highest grade adapted to properly protect the inserted insulator neck against the weather elements and that is otherwise admirably suited to the purpose intended.

It will be understood that various changes in the details and mode of manipulation may be resorted to in carrying out the described welding method of malnng sectional insulator caps or the like, such for instance asbuilding up my cap from more than two fragments and while the specification has been chiefl directed toward shaping my blanks by orging processes, this is likewise intended to include the e uivalent in stamped metal products, allwit out depart- -ing from the spirit and scope of my invention heretofore described and more particularly pointed out in the appended claims.

' Claims:

1. The method of making a built-up metal insulator cap comprising similar sections adapted to be adjoined in abutting relation, said method conslsting in forming in one 0peration a fragmental diametrically parted bell-shaped section having a dome element together with an arcuate skirt element ter-- minating in a transversely disposed rim edge that is cupped inwardly, and then adjoining a pair of such sections and uniting the abutting seams thereof to complete a. unitary interiorly chambered cap structure having a radiall undercut rim mouth.

2. T e method of forging a built-up metal product comprising sections adapted to be adjoined, said method consisting in' the following steps, viz: firstly, forming a relatively flat blank; secondly, deforming said blank in one operation into a fragmental bellshaped section having a dome wall element lowing steps, viz: firstly, forming a relatively fiat blank provided with a ridge of gathered stock; secondly, deforming said blank in one operation into a fragmental bellshaped section to constitute a dome-wall and an arcuate skirt wall terminating in a cupped-in rim edge, said ridge being forged into a solid rib-like reenforcement integrally disposed perimetrically of the last named wall; and thirdly, placing into abutment a plurality of such cap sections and welding the respective contiguous seams and likewise the abutting ends of said ribs to complete a unitary structure having an endless reenforcing rib.

4. The method of forging a built-up metal insulator cap comprising similar sections adapted to be adjoined in abutting relation, said method consisting in forming in one operation a fragmental bell-shaped section including a skirt wall together with an inte-' gral dome wall terminating in a cupped-in rim edge and simultaneously forming attachment means upon the last named wall, and then placing into abutment a plurality of such sections and uniting the contiguous to be adjoined in abutting relation, said method consisting in forging in one operation a fragmentary diametrically parted bell shaped section comprising a dome wall together with an integral skirt wall terminatmg in a transversely disposed semi-circular rim portion that is cupped inwardly and of which the complementary and regions are respectively reenforced by a seam lip; and secondly, placing into abutment the corresponding edges of such similar sections and welding the contiguous parting seams thereof to complete a unitary hollow structure having a reenforced rim weld.

In testimony whereof, I have herewith set my hand this 27th day of May, 1927.

GEORGE H. HIGGINS. 

